Sebastian Vettel remained fastest for Ferrari at the end of the penultimate day of 2020 pre-season Formula 1 testing, while Mercedes' Lewis Hamilton suffered a reliability setback on Thursday afternoon.
Vettel's 1m16.841s on C5s from the morning went unbeaten during the four-hour second session, but it wasn't all plain sailing for Vettel who also had a trip through the gravel in the morning that brought out the third red flag of the session.
AlphaTauri's Pierre Gasly put in a lap on the same rubber that was 0.225 seconds adrift of the top spot with under 15 minutes remaining.
Lance Stroll's C3-time of 1m17.118s from the morning session, ended up as the third-quickest time of the day overall for Racing Point.
Mercedes suffer setback
Things were not so good for defending champions Mercedes, as Hamilton spent more than an hour of the afternoon in the garage with an unexplained problem having taken over from morning runner Valtteri Bottas, only to finally emerge before stopping on track after just 14 laps.
Mercedes retired him from the session and he finished 13th overall under red flags, the team later revealing that he had an oil pressure anomaly.
When Hamilton did take to the track, he immediately began a long-run stint on the yellow-walled C3 rubber - for a long while lapping just ahead of Vettel, who was also conducting a long-run assessment.
But Hamilton's effort came to an end after 12 laps when his engine appeared to shut down suddenly as he exited the downhill Turn 5 left-hander, and he coasted up to the approach to Turn 7 before pulling over.
This caused the afternoon's only red flag, and Hamilton did not reappear again after that as Mercedes revealed the issue had been caused by an oil pressure anomaly that led to the engine shutting down as a precaution.
Racking up the laps
Williams' Nicholas Latifi finished on 160 laps for the day and fourth overall in the times behind Stroll thanks to his 1m17.313s from the morning.
Lando Norris was shuffled down from fourth in the morning to fifth in the afternoon, finishing ahead of morning-only runners Max Verstappen, Bottas and Esteban Ocon.
Kevin Magnussen finished ninth with 111 laps completed aboard his Haas, while Alex Albon climbed into the Red Bull for the afternoon and ended up 10th, with 61 laps logged.
Albon's 1m18.393s on the C2 tyres was 1.552s adrift of Vettel's day-best time.
Daniel Ricciardo took over from Ocon in the Renault for the afternoon, but he also did not trouble the top of the times and wound up 11th quickest - with a best time of 1m18.395s coming on the C3s.
Antonio Giovinazzi finished the day in 12th, as his 1m19.670s from the morning running - which had placed him ninth after the first four-hour session - remained his best lap for Alfa Romeo.